1. Field of the Invention
The present invention relates to a motor and, more particularly, to a motor allowing easy assembly.
2. Description of the Related Art
FIG. 1 shows a conventional motor 9 including a housing 91, a stator 92, a rotor 93, a retainer ring 94, and a positioning ring 95. The housing 91 includes a base 911 on which a shaft tube 912 is formed. A bearing 913 is mounted in the shaft tube 912 around which the stator 92 is mounted. The rotor 93 includes a shaft 931 rotatably extending through the bearing 913. The shaft 931 includes an annular groove 932 in an outer periphery thereof. The retainer ring 94 includes a central hole 941 and a plurality of cutouts 942 extending outward from an inner periphery defining the central hole 941, as shown in FIG. 2. The positioning ring 95 is mounted on top of the retainer ring 94. Such a motor is disclosed in Taiwan Patent Application No. 94147553 (Taiwan Patent No. 1283100) entitled “MOTOR FOR FAN.”
In assembly, the stator 92, the retainer ring 94, and the positioning ring 95 are firstly assembled in sequence. The shaft 931 is then inserted through the positioning ring 95 and the retainer ring 94 into the bearing 913. By providing the cutouts 942 in the retainer ring 94, the shaft 931 can be forcibly inserted through the central hole 941 of the retainer ring 94, with the retainer ring 94 being engaged in the annular groove 932. The retainer ring 94 prevents the rotor 93 from disengaging from the housing 91 during operation.
The retainer ring 94 abuts against an end face of the bearing 913 that only includes a guiding section for guiding the shaft 931 during assembly. The guiding section can not provide a space sufficient to allow deformation of the retainer ring 94. As a result, it is difficult to forcibly pass the shaft 931 through the central hole 941 of the retainer ring 94, leading to assembly inconvenience. Furthermore, a peripheral edge defining the central hole 941 of the retainer ring 94 is liable to break during forcible insertion of the shaft 931, adversely affecting the retaining function of the retainer ring 94 such that the retainer ring 94 can not effectively prevent the rotor 93 from disengaging from the housing 91.